Systemic adverse events during 2005 phacoemulsifications under monitored anesthesia care: a prospective evaluation.

BACKGROUND: The aim of the study was to evaluate the systemic adverse events triggering on-call anesthesiologist's intervention during 2005 phacoemulsification under topical anesthesia on a day-surgery monitored anesthesia care regimen. METHODS: Adverse events triggering an anesthesiologist call by the attending nurse were registered. Comorbidities (7 categories), age, gender, body mass index, ASA status, length of surgery, time of the day of surgery and operated eye (first/second) were analyzed as potentially predictive factors. Odds Ratios are expressed as OR (95% CI). RESULTS: The anesthesiologist was called in 433 (21.6%) cases: age (5-yr-OR 0.95 [0.91-0.99]), ASA status 3-4 (OR 1.37 [1.02-1.85]), positive neurological history (OR 1.60 [1.06-2.40]), positive psychiatric history (OR 2.56 [1.34-4.93]) and length of surgery (OR 1.03 [1.01-1.06]) were predictive of the anesthesiologist call. Arterial hypertension (10.3%) and agitation (9.5%) were the most frequent adverse events. Age (5-yr-OR 1.27 [1.16-1.38]) and ASA status 3-4 (OR 1.83 [1.30-2.56]) were predictive of arterial hypertension. Age (5-yr-OR 0.80 [0.76-0.85]), positive neurological history (OR 1.86 [1.10-3.14]) and positive psychiatric history (OR 4.48 [2.26-8.88]) were predictive of agitation. Interruption of surgery was never required. CONCLUSION: One-day cataract surgery performed under topical anesthesia with monitored anesthesia care required anesthesiologist intervention in 21.6% of cases, mainly because of agitation or hypertension. Agitation occurred more often in younger patients with neurological or psychiatric comorbidities. Hypertension occurred more often in older patients with higher ASA scores.

A comparison of epidural vs. paravertebral blockade in thoracic surgery.

AIM: Epidural analgesia is considered to be the best method of pain relief after major surgery despite its side-effects, which include hypotension, respiratory depression, urinary retention, incomplete or failed block, and, in rare cases, paraplegia. Paravertebral block is an alternative technique that may offer a comparable analgesic effect and a better side-effect profile. This study measured postoperative pain and respiratory function in patients randomized to receive either paravertebral block or epidural analgesia for pain control after thoracic surgery. METHODS: Twenty-four adult patients undergoing thoracic surgery were enrolled in a prospective and randomized clinical study. Patients were randomly allocated to receive either postoperative continuous paravertebral analgesia (N=12) or epidural analgesia (N=12) starting at pleura closure. Postoperative use of morphine, visual analogue scores, and spirometer data were collected for 72 hours after surgery as markers of pain relief. RESULTS: There was a statistically significant (P=0.003) increase in median (25th-75th percentiles) patient-controlled use of morphine, with values of 36 (22-42) mg in the paravertebral group vs. 9 (2-22) mg in the epidural group. This increase in morphine usage in the paravertebral group was statistically significant at 6, 24, 48, and 72 hours after surgery. Postoperative pain measured with the visual analogue score was not significantly different in the two groups. Spirometer values at 72 h were better in the epidural group than in the paravertebral group (P=0.03). CONCLUSIONS: Epidural analgesia is more efficient than paravertebral continuous block at reducing pain after thoracic surgery.

Non-invasive ventilation outside the Intensive Care Unit for acute respiratory failure: the perspective of the general ward nurses.

BACKGROUND: The introduction of non-invasive ventilation outside the Intensive Care Unit (ICU) is an increasing phenomenon, motivated by the shortage of intensive care beds and growing confidence with the technique. However, although general ward nurses are responsible for carrying out the daily management of the treatment and the extra monitoring it requires, their perspective on non-invasive ventilation (NIV) has never before been studied, and as a result their training is often neglected. METHODS: A questionnaire was administered to the nurses of four non-intensive wards. The questionnaire addressed several issues, including the extent of the nurses' involvement in the decision to start the treatment, their relationship with the ward physicians and the Medical Emergency Team (MET), the monitoring, incidence, and management of errors and complications, the adhesion to the prescribed ventilatory program, and the desired training. RESULTS: Out of 115 nurses, 90 completed the questionnaire (78.3%). Of this group, 67% did not feel involved in the decision-making process, and half felt they were inadequately informed. Approximately one third reported that they did not have adequate consultations with the doctors in the ward or with the MET. Only 13% of the nurses stated that the training was adequate (0% in medical wards). CONCLUSIONS: Nurses indicated a strong demand for training on NIV, in order to improve their involvement with the therapeutic program and for better communication with the MET and ward doctors. We conclude that active research towards understanding their point of view should be included as part of the quality control of NIV treatments outside the ICU.

Dilatative percutaneous tracheostomy during double antiplatelet therapy: two consecutive cases.

This article reports two cases of dilatative percutaneous tracheostomy performed on patients treated with double antiplatelet therapy. Both patients had cardiac arrest following myocardial infarction. After primary angioplasty with stent placement, a double antiplatelet therapy was started. Due to poor neurological outcome, dilatative percutaneous tracheostomy was performed on both patients. Antiplatelet therapy was not discontinued because of the unacceptable risk of stent thrombosis. No immediate or late hemorrhagic complications occurred. In our experience, dilatative percutaneous tracheostomy during double antiplatelet therapy can be safely performed in selected patients without other risk factors.

Effect of nitrous oxide on desflurane MACBAR at two target-controlled concentrations of remifentanil.

BACKGROUND: The aim of this prospective, randomized, double-blind study was to determine the effect of nitrous oxide on the desflurane requirement for blunting sympathetic response following surgical incision (MACBAR) when desflurane was combined with two different target-controlled concentrations of remifentanil (1 and 3 ng/mL). METHODS: A total of 103 patients, aged 20-50 years, ASA physical status I, scheduled to undergo general anesthesia for elective abdominal surgery, were randomly allocated to receive anesthesia with desflurane alone (Group A, n = 53), or with the addition of 60% nitrous oxide (Group N, n = 50). Patients of both groups were further assigned to receive a target-controlled plasma concentration of 1 ng/mL (Group A1, n = 27; Group N1, n = 26) or 3 ng/mL remifentanil (Group A3, n = 26, Group N3, n = 24). Sympathetic responses to surgical incision were determined after a 20 min period of constant end-tidal desflurane and target-controlled remifentanil concentrations. Predetermined end-tidal desflurane concentrations and the MACBAR for each group were determined using an up-and-down sequential allocation technique. RESULTS: A total of 98 patients completed the study. The MACBAR of desflurane was 5.2% (95% confidence interval [CI95: 4.9-5.5%]) in Group A1 and 2.7% (CI95: 2.6-2.8%) in Group N1 (P<0.001), while in Groups A3 and N3 the MACBAR of desflurane was 2.2% (CI95:2-2.4%) and 2% (CI95:1.9-2.2%), respectively (P<0.01). When considering a minimum anesthetic concentration (MAC) value with a contribution of 60% nitrous oxide (0.55 MAC) in this population, the combined MACBAR values (expressed as multiples of the MAC) were 1.9 MAC for group A1, 1 MAC for group N1, 0.8 MAC for group A3, and 0.7 MAC for group N3. CONCLUSION: The addition of 60% nitrous oxide reduces the MACBAR of desflurane by 52% when using a remifentanil concentration of 1 ng/mL, and reduces the MACBAR by 10% when using a remifentanil concentration of 3 ng/mL.

Predictive performance of 'Servin's formula' during BIS-guided propofol-remifentanil target-controlled infusion in morbidly obese patients.

BACKGROUND: The aim of this study was to assess the predictive performance of 'Servin's formula' for bispectral index (BIS)-guided propofol-remifentanil target-controlled infusion (TCI) in morbidly obese patients. METHODS: Twenty patients (ASA physical status II-III, age 32-64 yr) undergoing bilio-intestinal bypass surgery, were recruited. Anaesthesia was induced by using a TCI of propofol with an initial target plasma concentration of 6 microg ml(-1), then adapted to maintain stable BIS values ranging between 40 and 50. A TCI of remifentanil was added to achieve pain control and haemodynamic stability. For propofol, weight was corrected as suggested by Servin and colleagues. With ideal body weight (IBW) corrected according to formula suggested by Lemmens and colleagues. For remifentanil, weight was corrected according to IBW. Arterial blood samples for the determination of blood propofol concentrations were collected at different surgical times. The predictive performance of propofol TCI was evaluated by examining performance accuracy. RESULTS: Median prediction error and median absolute prediction error were -32.6% (range -53.4%; -2.5%) and 33.1% (10.8%; 53.4%), respectively. Wobble median value was 5.9% (2.5%; 25.2%) while divergence median value was -1.5% h(-1) (-7.7; 33.8% h(-1)). CONCLUSION: Significant bias between predicted and measured plasma propofol concentrations was found while the low wobble values suggest that propofol TCI system is able to maintain stable drug concentrations over time. As already suggested before, a computer simulation confirmed that the TCI system performance could be significantly improved when total body weight is used.

The effect of adding two target-controlled concentrations (1-3 ng mL -1 ) of remifentanil on MAC BAR of desflurane.

BACKGROUND AND OBJECTIVES: The aim of this prospective, randomized, double-blind study was to determine the effects of adding two different target-controlled concentrations of remifentanil (1 and 3 ng mL(-1)) on the desflurane requirement for blunting sympathetic responses after surgical incision (minimum anaesthetic concentration (MAC(BAR)). METHODS: 67 patients, aged 20-50 yr, ASA I, undergoing general anaesthesia for elective abdominal surgery were enrolled and randomly allocated to receive no remifentanil infusion (n = 21) or a target-controlled effect-site concentration of 1 ng mL(-1) (n = 24) or 3 ng mL(-1) remifentanil (n = 22). All patients were anaesthetized with propofol, cisatracurium and desflurane with a mixture of 60% nitrous oxide in oxygen. Sympathetic responses to surgical incision were determined after a 20-min period of stable end-tidal desflurane and target-controlled remifentanil concentrations. Predetermined end-tidal desflurane concentrations and the MAC(BAR) for each group were determined using an up-and-down sequential-allocation technique. RESULTS: The MAC(BAR) of desflurane was higher in the group receiving no remifentanil (6.25% [95% confidence interval: 5.9-6.5%]) as compared with patients of the groups receiving 1 ng mL(-1) (2.7% [2.6-2.8%]; P < 0.001) and 3 ng mL(-1) remifentanil (2% [1.9-2.2%]; P < 0.01). When considering a MAC value in this age population and the contribution of 60% nitrous oxide (0.55 MAC), the combined MAC(BAR) values, expressed as multiples of the MAC, were 1.9, 0.8 and 0.6 MAC, in the three groups, respectively. CONCLUSION: A target-controlled concentration of 1 ng mL(-1) remifentanil results in a 57% decrease in the MAC(BAR) of desflurane combined with 60% nitrous oxide. Increasing the target concentration of remifentanil to 3 ng mL(-1) produces a further 26% decrease in the MAC(BAR) values of desflurane.